There's two kinds of Printers competing with each other in the same way Betacord and VHS did with video tapes many years ago. Filament printers use a thin wire rod to build 3D models. The end result is very course for small stuff, but probably not so bad for larger scales. Resin Printers are the new kids on the block and they can create amazing models. I'm looking at a resin printer because the end result is much smoother. The resin is expensive, plus it needs to be UV cured, but look on Youtube to see what can be done for under AU$500 - US$300.
Print times are painfully slow. A simple model can take many hours to print. (24 hours is not uncommon.)
3D scanning is still pretty much a novelty, but there is free software available. Once again, visit Youtube. Generally, you will need to learn a program like Tinkercad (free) or source 3D patterns from the several sites specialising in shared files. As with Laser Cutting, 3D printing is a double whammy. You need to be proficient with a CAD program, then you need to learn how to use the printer. The learning curve can be very exciting, but it won't happen overnight. Anyone who tries to tell you differently is pulling your leg!
Look in your local area for a club called "Makers". They have the gear and there's a heap of people who can help you.